Engine/Transmission (1994 - 1998) Hard start on decline

[RWorth]

Went to start the truck and the mighty Cummins did not bust over on the initial spin of the starter like it usually does. I had the truck backed in the drive which put the front end ever so slightly down hill. The fuel system seemed to have lost its prime. When I got back home I again backed in the drive and then let the truck set for a while. After about 20 minutes or so I tried to start the truck and same thing the fuel sytem seemed to have lost its prime. Once the truck started I pulled the truck in forward in the drive to set overnight. This morning the truck when I bumped the starter the motor fired right up. I have checked the two fuel hose that deteoriate and they are ok. What I did notice was the end of the drain tube from the fuel filter was alittle wet and on top of the front differential was a spot as if the drain valve had been leaking. Looks like I am going to have to replace the filter drain valve and water sensor. Has anyone else seen this problem? Is there another place I should be looking for fuel leaks?





TIA



Roger

 

[PUMPERDUDE]

I' start with the easiest stuff first. If your WIF valve drain is leaking, change that first. After that I'd change your overflow valve because its about time to give out anyway and its easy. My 95's overflow valve spring broke a year ago. Order it from Piers. If that doesnt fix the problem I'd look very hard at your return line. Its hard to see if it is bad because its goes bad right under the intake . My 95's blew 6 months ago and I mean BLEW. I'd bite the bullet and change it just for peace of mind. While your in there cursing and bleeding ,change the supply line too. Something else that comes to mind ,though not very common is a hole in your pickup tube in the fuel tank. Parking at diffferent angle might expose the hole?Just a guess. Good luck!

 

[RWorth]

Thanks Pumperdude. I thought about the pickup tube in the tank as well, but I haven't heard of anyone else to have the same problem.

 

[Andy Redmond]

I'd try the return line first (5/16 fuel line rated for SAE 30R7 (fuel rating)). In changing several sending units, I've seen the hard plastic lines chaffed through enough to create the pin hole effect. The slides on the tank module had allowed the lines to chaff. If you go fill it up and the problem goes away, you likely found your culprit. Might be new tank module time



I've repaired several lines on the tank module, but sufficent time hasn't told us if its a permanent repair (only 6 mos and counting so far).



Good luck,



Andy

 

[illflem]

The above suggestions are right on but starting usually isn't effected by the direction of slope the truck is parked on with those problems. They will cause problems all the time. What is effected by tilt though are bad check valves in the lift pump. Unfortunately the check valves aren't available separately, you have to buy the whole pump. If you had a FP gauge you would have also seen it slowly dropping the last few weeks.

 

[RWorth]

Thanks to those who replied. I pulled the fuel filter after I got home from work. While I was removing the filter I could feel diesel on the WIF valve. I installed the new WIF valve on a new filter (Fleet Guard) and primed the filter with the hand pump. The motor fired right up. I let it set for awhile and went to start again slight hesitation. Drove the truck to my friends house and parked on concrete driveway after about 15 minutes we noticed a wet spot on the driveway. I then re-checked the WIF valve and it was leaking. I snugged the valve up with some pliers. I then backed the truck to where the front end was on the decline. I tried starting this morning and it fired right up. I feel that the problem is fixed now. Looks like the WIF valve was leaking.





Thanks,

Roger